1. Field of the Invention
The present invention relates to a chuck with two oppositely disposed clamping jaws, each of which comprises a base jaw and a top jaw, with the base jaws being guided in an annular chuck body that has a central clamping space in such a way as to be movable in a radial direction, and with each base jaw being centrally driven by a wedge-type member that is mounted in the chuck body in such a way as to be essentially axially movable.
2. Description of the Prior Art
Chucks of this general type are known. Projecting workpieces are held with such chucks, whereby the workpieces, which are disposed in the central clamping space of the annular chuck body, are held in such a way by the clamping jaws, which are disposed radially in the annular chuck body, that clamping jaws which extend beyond the end face of the chuck body are avoided. Clamping jaws that extend beyond the end face of the chuck body are subjected to a great expansion due to clamping and centrifugal forces.
With the chucks of the aforementioned type, the clamping force of the clamping jaws is introduced directly into the annular chuck body in the clamping plane, so that the reaction forces in the chuck body, in contrast to the situation where projecting clamping jaws are present, corresponds to the clamping force without amplification due to the length of lever arms.
A drawback of the heretofore known chuck constructions of the aforementioned type is that a central piston is used that leads to an undesired increase of the overall axial length and hence, while at the same time reducing the clamping space in the annular chuck body, leads to an increase of the maximum torque that occurs during machining and that is exerted upon the spindle.
It is an object of the present invention to provide a centrally clamping, two-jaw chuck of the aforementioned general type that has a short, overall axial length and a large clamping space.